1. Field of the Invention
The present invention relates generally to a shape recognition device which can detect the existence/absence or normal/abnormal state of an object, and the shape and movement of the object. In particular, the present invention relates to the construction of a shape detection device for detecting the shape and movement of a conductive object by directly contacting the object.
2. Description of the Related Art
A device has been proposed for recognizing the shape of human fingerprints as one of the conventional devices for recognizing and discriminating the shape of an object. This fingerprint recognition device discriminates and identifies the owner of a specified fingerprint, and accordingly it can selectively permit his or her access to a specified device.
The conventional fingerprint recognition device solves the problem involved in mechanical locks which may be easily released by a person who understands the structure of the mechanical locks well and has undesirable intentions, and permits only specified persons access to the specified target by recognizing the fingerprints having inherently different shapes from one another.
The conventional fingerprint recognition device may employ either type of an optical detection section using an image pickup device, that is, an indirect contact type shape detection section for being in indirect contact with the human body or the object and detecting the amount of electric charge differently charged thereon in accordance with the minute differences in the distance between the peaks and valleys in the fingerprint or the object, or a direct contact type shape detection section for being in direct contact with the human body or the object and detecting minute electric signal flowing therethrough.
FIG. 1 is a block diagram of a conventional shape recognition device for recognizing the shape of an object. FIGS. 2A and 2B are views illustrating the structure and the use of an indirect contact type shape detection section of a conventional shape recognition device. FIGS. 3A and 3B are views illustrating the structure and the use of a direct contact type shape detection section of a conventional shape recognition device.
The construction and operation of the conventional device for recognizing the shape of the fingerprint or the object will be explained in detail with reference to the accompanying drawings.
Referring to FIG. 1, the conventional shape recognition device includes a shape detection section 10 for detecting the minute electric signal flowing through a fingerprint 40 or an object or for detecting the amount of charge charged thereon, a shape discrimination section 20 for discriminating the shape of the fingerprint or the object by comparing electric signals outputted from the shape detecting section 10 corresponding to the shape of the fingerprint or the object and outputting a corresponding control signal, and a display/control section 30 for performing the necessary shape display or control function in accordance with the control signal outputted from the shape discrimination section 20.
The conventional optical shape detection section 10 using an image pickup device, not being illustrated in the drawings, has drawbacks in that it is expensive and it is difficult to ascertain the authenticity of the object if a photograph is used for the shape detection instead of the actual object, thereby limiting its use.
According to the conventional indirect contact type shape detection section 10 as shown in FIGS. 2A and 2B, the charges residing on peaks 42 and valleys 44, which are protrusions and recesses of the fingerprint 40 or the object, respectively, are detected by a plurality of first electrodes 121 and second electrodes 122 respectively arranged at regular intervals which are determined to be smaller than those between the peaks 42 and valleys 44. The first and second electrodes 121 and 122 are respectively formed in a line on the upper portion of an insulating substrate 110 by a semiconductor manufacturing process, and electrically connected to the shape discrimination section 20 through signal transmission lines (not illustrated).
The upper surface of the first and second electrodes 121 and 122 are coated with an anti-wear dielectric 130.
As described above, the first and second electrodes 121 and 122 of the indirect type shape detection section 10 detect the electric charges residing on the fingerprint 40 or the object. At this time, the amounts of charge detected by the respective electrodes 121 and 122 differ from one another due to the minute differences in distance between the peaks 42 and the valleys 44 of the fingerprint 40 or the object.
The electrodes may be arranged in multiple lines, and the shape detection signals detected by the respective electrodes in accordance with the different amounts of charge residing on the fingerprint 40 or the object are applied to the shape discrimination section 20 through the signal transmission lines.
The shape discrimination section 20 processes and converts the received signals into data corresponding to the shape of the fingerprint 40 or the object, discriminates the shape of the fingerprint 40 or the object by comparing the data with reference data stored therein, and then outputs a corresponding control signal to the display/control section 30, so that the display/control section 30 controls the operation of a security device.
Also, in the event that the fingerprint 40 or the object detected by the shape detection section 10 moves in a certain direction, the shape discrimination section 20 discriminates the moving direction of the object by processing the signals sensed by the electrodes, which reflect the variation of the sensed charge amounts, and provides the corresponding control signal to the display/control section 30. Accordingly, it can perform the function of a mouse or a joystick used in a multimedia appliance.
However, the conventional indirect contact type shape detection device has drawbacks in that the anti-wear dielectric 130 for contacting the fingerprint 40 or the object is finally worn away by the repeated use thereof, and this causes an error to occur in detecting the amount of charge in accordance with the minute differences in distance between the electrodes and the fingerprint 40 or the object, so that the shape or the position of the object cannot be accurately identified accurately.
There are limitations in increasing the anti-wear characteristic of the dielectric 130, and the indirect contact type shape detection section is expensive since it is manufactured using a semiconductor thin film manufacturing process, thereby limiting its use.
The conventional direct contact type shape detection section 10 as shown in FIGS. 3A and 3B has been proposed to solve the problems of the indirect contact type shape detection section.
According to the conventional direct contact type shape detection section 10 of FIGS. 3A and 3B, a plurality of first row holes 161 and second row holes 162, the diameter of which does not exceed 0.1 mm at maximum, are formed on an insulating substrate 150 by a laser boring or drilling, or by other specified methods. At this time, the space between the holes is determined not to exceed a maximum of 0.1 mm.
Thereafter, the first row electrodes 171 and second row electrodes 172 are formed by filling the first row holes 161 and the second row holes 162 with conductive metal by plating, application, insertion, etc. The lower portions of the first and second row electrodes 171 and 172 are respectively connected to signal transmission lines 175 formed on the lower surface of the insulating substrate by plating, application, printing, etc. The signal transmission lines 175 transmit the signals detected by the first and second row electrodes 171 and 172 to the shape discrimination section 20.
The minute electric signals flowing through the human body or the object are detected by the first and second row electrodes 171 and 172 formed on the substrate 150 which are respectively in direct contact with the peaks 42 of the fingerprint 40 or the object. The sensed electric signals are applied to the shape detection section 10, and the shape detection section 10 transmits the sensed electric signals to the shape discrimination section 20. The following operation will be the same as the conventional indirect contact type shape detection section as described above.
However, the conventional direct contact type shape detection device has drawbacks in that the perforation of the plurality of first and second row holes 161 and 162 on the substrate 150 as well as the filling of the holes 161 and 162 with the conductive metal by plating, application, insertion, etc. requires a high degree of technical accuracy which causes the production rate of inferior goods to increase, so that productivity decreases and the manufacturing cost increases, thereby limiting its popular use.
It is the object of the present invention to solve the problems involved in the related art, and to provide a direct contact type shape detection device which can lengthen its life span without being affected by the wear of the dielectric which can be manufactured inexpensively with superior productivity.
In one aspect of the present invention, there is provided a shape detection device comprising:
a shape detection section including two substrates each having a plurality of electrodes formed on one surface thereof, the substrates being arranged to face each other with a predetermined space therebetween and being bonded together by an insulating adhesive filled in the space between the substrates;
a shape discrimination section for discriminating a shape or the moving direction of an object in accordance with sensed signals outputted from the shape detection section, and outputting a corresponding control signal; and
a display/control section for performing a display or control function in accordance with the control signal outputted from the shape discrimination section.
In another aspect of the present invention, there is provided a method of manufacturing a shape detection device comprising the steps of:
forming a plurality of electrodes on insulating substrates;
arranging the substrates to face each other with a predetermined space therebetween;
bonding the substrates together by filling an insulating adhesive into the space between the substrates; and
grinding edge portions of the electrodes formed on the substrates bonded together.